Noise suppressor for vehicle digital system

Claim 2

A noise suppressor for use with an automotive vehicle control system including a power unit connected through a power line to a power source, and a digital computer powered by said power unit and operable in synchronism with clock pulses, said digital computer connected to signal lines through which vehicle running condition indicative signals are fed thereto and control signals are fed therefrom, the suppressor comprising: a plurality of capacitors, each connected in shunt between each of selected ones of said signal lines and ground; an inductor connected in series with said power line; a capacitor connected in shunt between said power line and ground; and means for shielding said digital computer, thereby minimizing transmission of high frequency signals caused by the clock pulses through said signal and power lines.

Claim 3

The noise suppressor of claim 1 wherein each of said capacitors has a capacity value ranging between 100 PF and 1,000 PF and the inductor has an inductance value ranging between 1μ and 100 mH.

Claim 4

The noise suppressor of claim 1 wherein said shielding means comprises a grounded metal casing enclosing said digital computer, said power unit, said inductor and said capacitors.

Claim 5

The noise suppressor of claim 3 further including a metal plate enclosed by said metal casing, said capacitors being through type capacitors fitted in through-holes formed in the plate.

Claim 6

The noise suppressor of claim 1 wherein said shielding means comprises: a first grounded metal casing enclosing said digital computer and said power unit, and a second metal casing enclosing said inductor and said capacitors, said second metal casing electrically connected to said first metal casing.

Claim 7

The noise suppressor of claim 5 further including a metal plate enclosed by said second metal casing, said capacitors being through type capacitors fitted in through-holes formed in the plate.

Claim 8

Apparatus for substantially preventing electronic noise from being coupled to communication components of an automotive vehicle from a digital control system of the automotive vehicle, the control system being energized by a power unit connected by a power line to be responsive to a DC power source of the vehicle, said power unit being connected to a supply terminal of a digital computer by a supply lead, said digital control system being connected to unshielded leads carrying signals indicative of conditions of the vehicle, said computer deriving pulses, the pulses having a tendency to be coupled from said digital control system to the leads to have a tendency to establish electronic noise that interferes with the communication components, the apparatus comprising grounded metal shield means encasing the digital computer, power unit and supply lead for shielding the communication components from the computer, power unit and supply lead, the power line and signal carrying leads extending through the metallic shield, a shunt capacitor connected between the power line and ground, a separate shunt capacitor connected between each of the signal carrying leads and ground, an inductor series connected with the power line, the capacitors and inductor having values to attenuate the electronic noise to a level that does not substantially interfere with the communication components and being located within the shield means.

Claim 9

Apparatus for substantially preventing electronic noise from being coupled to communication components of an automotive vehicle from a digital control system of the automotive vehicle, the control system being energized by a power unit connected by a power line to be responsive to a DC power source of the vehicle, said power unit being connected to a supply terminal of a digital computer by a supply lead, said digital control system being connected to unshielded leads carrying signals indicative of conditions of the vehicle, said computer deriving pulses, the pulses having a tendency to be coupled from said digital control system to the leads to have a tendency to establish electronic noise that interferes with the communication components, the apparatus comprising grounded metal shield means encasing the digital computer, power unit and supply lead for shielding the communication components from the computer, power unit and supply lead, the power line and signal carrying leads extending through the metallic shield, a shunt capacitor connected between the power line and ground, a separate shunt capacitor connected between each of the signal carrying leads and ground, an inductor series connected with the power line, the capacitors and inductor having values to attenuate the electronic noise to a level that does not substantially interfere with the communication components and being located within the shield means.

Claim 10

The apparatus of claim 7 wherein the metal shield means includes first and second separate metal containers in which are respectively located (1) the computer, power unit and supply lead and (2), the capacitors and inductor; and means for electrically connecting said containers to each other so each is grounded, a bundle including the power and signal wires extending through walls of the containers.

Claim 11

The apparatus of claim 8 wherein the first and second containers respectively include first and second substrates, a metal plate located between the substrates, said plate being carried by one of the containers and including through holes, said capacitors being carried by said plate and being fitted to extend through the holes, said capacitors having opposite electrodes connected to leads on the substrate.

Claim 12

The apparatus of claim 8 wherein the second container includes a substrate having opposite first and second faces respectively carrying signal line and ground patterns, the ground patterns being in abutting mechanical and electrical relation with the one container, the signal line patterns being mechanically and electrically spaced from the containers, one of said capacitors having first and second leads respectively electrically and mechanically connected to the ground and signal line patterns, the first lead extending through a hole in the substrate, the capacitor having a body proximate the first face and remote from the second face.

Claim 13

The apparatus of claim 8 wherein the second container includes an interior metal partition having edges electrically and mechanically abutting against metal exterior wall means of the second container, said partition having an aperture through which one of said capacitor fits.

Claim 14

In combination with an automotive vehicle, radio frequency communication components, a digital control system including a digital computer, sensors for deriving input signals for the digital control system, the digital control system deriving pulses, unshielded leads connected to have a tendency to carry the pulses from the control system to the sensors and to carry the input signals from the sensors to the control system, the pulses carried by the unshielded leads from the control system to the sensors having a tendency to establish radio frequency interference that interferes with the communication components, apparatus for substantially preventing the radio frequency interference from being coupled to the communication components, including: grounded metal shield means encasing the digital control system for electromagnetically shielding the communication components from the control system, the leads extending through the metal shield means, a separate shunt capacitor connected between each lead and ground, each shunt capacitor being encased within the shield means, the capacitors having values to attenuate the radio interference to a level such that the interference does not substantially interfer with the communication components so the radio interference is confined to the interior of the shield means.

Claim 15

In combination with an automotive vehicle, radio frequency communication components, a digital control system including a digital computer, sensors for deriving input signals for the digital control system, the digital control system deriving pulses, unshielded leads connected to have a tendency to carry the pulses from the control system to the sensors and to carry the input signals from the sensors to the control system, the pulses carried by the unshielded leads from the control system to the sensors having a tendency to establish radio frequency interference that interferes with the communication components, apparatus for substantially preventing the radio frequency interference from being coupled to the communication components, including: grounded metal shield means encasing the digital control system for electromagnetically shielding the communication components from the control system, the leads extending through the metal shield means, a separate shunt capacitor connected between each lead and ground, each shunt capacitor being encased within the shield means, the capacitors having values to attenuate the radio interference to a level such that the interference does not substantially interfer with the communication components so the radio interference is confined to the interior of the shield means.

Claim 16

The combination of claim 12 further including a bundle in which are located the unshielded leads between the sensors and shield means, lead wires for the communication components also being located in said bundle, the lead wires and unshielded leads in the bundle being electromagnetically coupled.

Claim 17

The combination of claim 12 or 13 further including a DC power unit for the digital control system, a first power lead connected between the power unit and the digital control system, a second power lead connected between a DC power supply of the vehicle and the power unit, a series inductor in the second power lead, a shunt filter capacitor connected between ground and a common connection for one terminal of the inductor and an ungrounded terminal of the DC vehicle power supply, the second power lead having a tendency to carry radio frequency interference tending to interfer with the radio frequency communication components, the series inductor and shunt filter capacitor having values to reduce the radio frequency interference on the second power lead so it does not interfer substantially with the radio frequency communication components, said power unit, first power lead, series inductor, shunt filter capacitor and the second power lead between a second terminal of the inductor and the power unit being encased in the shield means.

Claim 18

The combination of claim 14 wherein the shield means includes first and second separate metal containers in which are respectively located (1) the DC power unit, digital control system and first power lead, and (2), the capacitors and inductor; and means for electrically connecting said containers to each other so each is grounded, a bundle including the power and signal wires extending through walls of the containers.

Claim 19

The combination of claim 14 wherein the shield means includes first and second separate metal containers in which are respectively located (1) the DC power unit, digital control system and first power lead, and (2), the capacitors and inductor; and means for electrically connecting said containers to each other so each is grounded, a bundle including the power and signal wires extending through walls of the containers, the first and second containers respectively including first and second substrates, a metal plate located between the substrates, said plate being carried by one of the containers and including through holes, said capacitors being carried by said plate and being fitted to extend through the holes, said capacitors having opposite electrodes connected to leads on the substrate.

Claim 20

The combination of claim 14 wherein the shield means includes first and second separate metal containers in which are respectively located (1) the DC power unit, digital control system and first power lead, and (2), the capacitors and inductor; and means for electrically connecting said containers to each other so each is grounded, a bundle including the power and signal wires extending through walls of the containers, the second container including a substrate having opposite first and second faces respectively carrying signal line and ground patterns, the ground patterns being in abutting mechanical and electrical relation with the one container, the signal line patterns being mechanically and electrically spaced from the containers, one of said capacitors having first and second leads respectively electrically and mechanically connected to the ground and signal line patterns, the first lead extending through a hole in the substrate, the capacitor having a body proximate the first face and remote from the second face.

Claim 21

The combination of claim 14 wherein the shield means includes first and second separate metal containers in which are respectively located (1) the DC power unit, digital control system and first power lead, and (2), the capacitors and inductor; and means for electrically connecting said containers to each other so each is grounded, a bundle including the power and signal wires extending through walls of the container, the second container including an interior metal partition having edges electrically and mechanically abutting against metal exterior wall means of the second container, said partition having an aperture through which one of said capacitors fits.